To ease city congestion, Curitiba zones its tallest buildings along main transit corridors.

Zoning

It was never hard to find my way through Curitiba, with a telltale band of skyscrapers cutting across the city's skyline and jutting above its main avenues. I learned early on that whenever I was lost, I only had to scan the horizon for the tallest buildings and follow them until I reached a main bus line. But that quick reference point for visitors also is a lesson in smart zoning.

Throughout the first half of the 20th century, Curibita's growth spurts demanded more building space. As the amount of available space diminished, most architects designed the city to grow up, not out. But they knew the high-rise offices and apartment buildings would also one day fill to capacity, so they zoned them by areas next to mass transit routes -- keeping traffic pressure off secondary streets and people within short walking distance of bus lines. But some builders of the era tore down hundreds of the city's old colonial landmarks, and with them, part of Curitiba's connection to its past.

In 1964, a new corps of urban planners wanted some assurances that Curitiba would grow within reason and without losing any more of its history. In addition to accommodating an expanding population with new homes and places to work, they envisioned more parks, museums and cultural centers around old Curitiba landmarks. In their Master Plan for Curitiba, they created a historic zone, preserving old buildings by permitting the transfer of building rights from historic plots to vacant ones. Thus, owners of old buildings who couldn't afford to restore them could trade them to the city and build elsewhere without paying municipal taxes.

The results of the urban planners' efforts are stretches of historic blocks, with 100-year-old buildings restored and preserved. I walked through the historic Largo da Ordem, one of the liveliest and most popular areas of the city, to see how the old buildings are being used as bustling museums, bars, restaurants and shops. Throughout the evening, people filled up outdoor dinner tables surrounded by charming antiquity -- in stark contrast to the modern, cubed architecture elsewhere in the city. A performance space, with vaulted ceilings, impressive fountains and small waterways, is at the center of the vibrant Largo da Ordem. One Sunday morning, I walked out to find the area closed off to cars for the weekly fair: The cobblestone streets were filled with thousands of people listening to music, shopping for handicrafts and eating everything from coconuts to weinerschnitzel.